ON THE THEORY OF RADIATIVE CAPTURE OF 1S ORBITAL ELECTRONS

1962 ◽  
Vol 40 (12) ◽  
pp. 1765-1771 ◽  
Author(s):  
Guy Paquette
Keyword(s):  
Radiative Capture ◽  
Electromagnetic Interaction ◽  
Relativistic Effects ◽  
High Energy ◽  
Gamma Spectrum ◽  
High Energy Part ◽  
Energy Part ◽  
Spectrum Intensity ◽  
Retardation Effects ◽  
Nonrelativistic Calculation

A nonrelativistic calculation of the continuous gamma spectrum accompanying the capture of 1S orbital electrons in A37 is presented. The calculation takes into account the retardation effects in treating the electromagnetic interaction. A comparison with the relativistic calculation of Martin and Glauber (1958) shows that relativistic effects and screening corrections do not affect the high-energy part of the gamma spectrum. On the other hand, the retardation effects are important over the whole spectrum, except at the very lowest photon energies. The method employed in the calculation allows one to ascertain the relative importance of various intermediate states in their contribution to the spectrum intensity.

Compact back-scattered electrons' energy analyzer for standard SEM

1994 ◽  
Vol 52 ◽  
pp. 488-489
Author(s):  
S. Likharev ◽  
A. Kramarenko ◽  
V. Vybornov
Keyword(s):  
Depth Resolution ◽  
High Energy ◽  
Primary Beam ◽  
Layer By Layer ◽  
Energy Analyzer ◽  
High Energy Part ◽  
Small Window ◽  
Energy Part ◽  
Wide Range ◽  
High Voltage Supply

At present time the interest is growing considerably for theoretical and experimental analysis of back-scattered electrons (BSE) energy spectra. It was discovered that a special angle and energy nitration of BSE flow could be used for increasing a spatial resolution of BSE mode, sample topography investigations and for layer-by layer visualizing of a depth structure. In the last case it was shown theoretically that in order to obtain suitable depth resolution it is necessary to select a part of BSE flow with the directions of velocities close to inverse to the primary beam and energies within a small window in the high-energy part of the whole spectrum.A wide range of such devices has been developed earlier, but all of them have considerable demerit: they can hardly be used with a standard SEM due to the necessity of sufficient SEM modifications like installation of large accessories in or out SEM chamber, mounting of specialized detector systems, input wires for high voltage supply, screening a primary beam from additional electromagnetic field, etc. In this report we present a new scheme of a compact BSE energy analyzer that is free of imperfections mentioned above.

Spectrally Resolved Cathodoluminescence (SRCL) of Hydrothermal ZnO crystals

2005 ◽  
Vol 878 ◽  
Author(s):  
J. Mass ◽  
M. Avella ◽  
J. Jiménez ◽  
M. Callahan ◽  
E. Grant ◽  
...  
Keyword(s):  
High Energy ◽  
Luminescence Spectra ◽  
Growth Sector ◽  
High Energy Part ◽  
Spectral Signatures ◽  
Energy Part ◽  
Good Crystalline Quality ◽  
Recombination Centers ◽  
Band Tailing ◽  
Spectrally Resolved

AbstractLarge hydrothermal ZnO crystals were grown using 3N NaOH, 1N KOH and 0.5N Li2CO3mineralizer. The crystals were studied by cathodoluminescence (CL), showing a good crystalline quality. Different growth regions were identified by CL imaging. These regions were characterized by their corresponding luminescence spectra, showing that the incorporation of impurities and non radiative recombination centers depend on the growth sector. The surface is shown to introduce band tailing modifying the high energy part of the spectrum. The main spectral signatures of each sector are discussed.

On the High Energy Part of theK40β-Spectrum

1948 ◽  
Vol 74 (1) ◽  
pp. 102-103 ◽  
Author(s):  
S. Franchetti ◽  
M. Giovanozzi
Keyword(s):  
High Energy ◽  
High Energy Part ◽  
Energy Part

scholarly journals Новые линии в спектрах ИК люминесценции высокого разрешения монокристаллов SiC политипов 4H и 6H

2020 ◽  
Vol 128 (9) ◽  
pp. 1264
Author(s):  
К.Н. Болдырев ◽  
Д.Д. Гуценко ◽  
С.А. Климин ◽  
Н.Н. Новикова ◽  
Б.Н. Маврин ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Temperature ◽  
Single Crystals ◽  
Absorption Spectra ◽  
High Energy ◽  
High Quality ◽  
High Energy Part ◽  
Infrared Luminescence ◽  
Energy Part ◽  
First Time

Low-temperature infrared luminescence and high-resolution absorption spectra of undoped high-quality SiC single crystals of hexagonal modifications 4H and 6H were investigated. Narrow lines with widths less than 0.2 cm^(-1) were detected, several of which were observed for the first time. It was found that some of the lines in the 4H and 6H modifications have a similar structure, however, the lines in SiC-4H are shifted to the high-energy part of the spectrum by ~ 180 cm^(-1). For the most intense quartet in the region of 1.3 μm, the energy scheme of the levels for both 4H and 6H modifications were constructed.

scholarly journals Synthesis, spectroscopic, electrochemical and photophysical properties of high band gap polymers for potential applications in semi-transparent solar cells

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Peshawa O. Amin ◽  
Kamal Aziz Ketuly ◽  
Salah Raza Saeed ◽  
Fahmi F. Muhammadsharif ◽  
Mark D. Symes ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Solar Cells ◽  
Band Gap ◽  
Optical Conductivity ◽  
Visible Region ◽  
High Energy ◽  
Electromagnetic Spectrum ◽  
High Energy Part ◽  
Energy Part

Abstract Background The design of new polymers able to filter the electromagnetic spectrum and absorb distinctly in the UV and high-energy part of visible spectrum is crucial for the development of semi-transparent solar cells. Herein, we report on the synthesis and spectroscopic, electrochemical, and photophysical characteristics of three new polymers, namely (i) Poly(triamterene-co-terephthalate), (ii) Poly[triamterene-co- 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-p,p′-disulfonamide], and (iii) Poly(5-hydroxyindole-2-carboxylate) that might show promise as materials for semi-transparent solar cells. Results The energy band gap, refractive index, dielectric constant, and optical conductivity of the electron donor polymer, poly(triamterene-co-terephthalate), were determined to be 2.92 eV, 1.56, 2.44 and 2.43 × 104 S cm−1, respectively. The synthesized electron acceptor polymers showed a relatively high refractive index, dielectric constant, and optical conductivity. The presence of a direct allowed transition was confirmed between intermolecular energy bands of the polymers. Conclusions The polymers showed relatively high energy gap and deep HOMO levels, making them strong absorbers of photons in the UV region and high energy part of the visible region. The synthesized donor and acceptors performed well relative to P3HT and fullerenes due to the close match of the HOMO and LUMO levels. With further development, the polymers could be viable for use as the active layers of semi-transparent solar cells.

scholarly journals The low energy β-rays of radium E

1934 ◽  
Vol 147 (862) ◽  
pp. 442-454 ◽  
Keyword(s):  
Energy Loss ◽  
Continuous Spectrum ◽  
Energy Region ◽  
High Energy ◽  
Experimental Information ◽  
Low Energy ◽  
Expansion Chamber ◽  
High Energy Part ◽  
Energy Part ◽  
Γ Ray

The object of this work was to obtain information about the shape of the low energy end of the continuous β-ray spectrum of radium E, an element convenient because of its negligible γ-ray emission. The failure of theory to explain the continuous spectrum makes it of interest to obtain all possible experimental information, and although much is now known about the high energy part of the curve, the low energy region has remained obscure owing to certain experimental difficulties. The chief of these has been the contamination of the low energy end of the curve by rays reflected with unknown energy loss from the material on which the radioactive body was deposited. This effect can be eliminated by mounting it on sufficiently thin metal leaf so that no particles can be reflected with appreciable loss of energy. Such a source would be too weak to use in a magnetic spectrograph, and the method therefore adopted in this work was out to mount it in a Wilson expansion chamber and take stereoscopic photographs from which the ranges of any slow tracks formed could be measured, a method already used by the writer for radium D.

scholarly journals Simulations and Modeling of Intermediate Luminosity Optical Transients and Supernova Impostors

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 82 ◽  
Author(s):  
Amit Kashi
Keyword(s):  
Central Star ◽  
High Energy ◽  
Gravitational Energy ◽  
High Energy Part ◽  
Classical Novae ◽  
Energy Part ◽  
Optical Transients ◽  
Hydrodynamical Simulations ◽  
Simulations And Modeling ◽  
Optical Transient

More luminous than classical novae, but less luminous than supernovae, lies the exotic stellar eruptions known as Intermediate luminosity optical transients (ILOTs). They are divided into a number of sub-groups depending on the erupting progenitor and the properties of the eruption. A large part of the ILOTs is positioned on the slanted Optical Transient Stripe (OTS) in the Energy-Time Diagram (ETD) that shows their total energy vs. duration of their eruption. We describe the different kinds of ILOTs that populate the OTS and other parts of the ETD. The high energy part of the OTS hosts the supernova impostors—giant eruptions (GE) of very massive stars. We show the results of the 3D hydrodynamical simulations of GEs that expose the mechanism behind these GEs and present new models for recent ILOTs. We discuss the connection between different kinds of ILOTs and suggest that they have a common energy source—gravitational energy released by mass transfer. We emphasize similarities between Planetary Nebulae (PNe) and ILOTs, and suggest that some PNe were formed in an ILOT event. Therefore, simulations used for GEs can be adapted for PNe, and used to learn about the influence of the ILOT events on the central star of the planetary nebula.

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